Field of the Invention
The present invention relates to the additional supply of respiratory oxygen to a patient. This supply is provided in addition to the natural supply of air of the atmosphere only during a part of the inspiratory phase. The additional supply is initiated by the detection or the anticipated detection, of the start of an inspiratory phase relative to the atmospheric pressure in a detecting chamber having an electronic sensor.
DESCRIPTION OF THE PRIOR ART
French patent No. 84 17,236 discloses an electronic sensor with a windbag equipped with a strip which is interposed in the optical path upon an inspiratory depression. This brings about, for a given lapse of time, the opening of an electrically controlled valve supplying breathable gas. This mode of operation is capable of providing good sensitivity provided there is a fine adjustment in the position of the various cooperating parts, since adjusment is generally necessary from time to time.